Sudden Green Hair Algae Explosion

Dom · Sep 11, 2018

I have a small 15 gallon reef set up. It includes a sump with about 5 additional gallons. So for the purpose of this post, lets call total water volume 20 gallons.

In this system, I have one side of the sump set up as a refugium and the other side holds the return pump. There is mechanical filtration only. There is one 3 pound piece of live rock in the middle of the display, and there is a bag of Chemipure Elite dropped in the overflow.

Having always enjoyed success with the "1 Pound per Gallon" live rock rule, based on this, I knew I was 15-20 pounds lite.

I didn't want to risk hitch-hikers, so I decided to go with dry rock. I contacted Bulk Reef Supply and chatted with a rep (I won't be mentioning names).

I asked: " Can dry rock be used right away? "

I forget how they put it exactly, but the message was essentially: "Give it a good rinse and it can go right in".

I ordered 15 pounds.

When it came, it looked exactly as expected; pure white, just like a piece of live rock I left on a sunny window for a year.

There were a total of three pieces. And each piece, one at a time, was placed into a 5 gallon bucket with the garden hose as I agitated the piece. The water started out with a lot of silt once the rock was submerged, but within a few minutes, the water was clear and I moved on to the next piece.

This tank had excellent water clarity and no algae growth as configured. I attribute this to weekly 25% water changes.

But since adding the dry rock, I have fields of green hair algae covering portions of the substrate as well as the entire piece of live rock previously in the tank.

There a pair of the nastiest tomato clowns in the tank and I am sure they can stand up to what's going on.

I'm sure it is the dry rock causing the problem
Can someone please explain to me why this happened?

Thanks
Dom

Retro Reefer · Sep 11, 2018

Lots of organics on most dry rock that need to be thoroughly cleaned off, people typically use pressure washers, bleach or acid baths to clean it prior to cycling.

Dom · Sep 11, 2018

Retro Reefer said:
Lots of organics on most dry rock that need to be thoroughly cleaned off, people typically use pressure washers, bleach or acid baths to clean it prior to cycling.

Ugh. I wonder why I was advised with "rinse and in..."?

"Cycling". Are you saying I should have cycled water in a bucket with the rock in it?

reefes pieces · Sep 11, 2018

I wouldn't blame the BRS rep as technically it's true in that it typically won't cause a cycle due to lack of organics in the rock. However, new rock can leach out phosphates which could be attributing to your break out. Did you happen to know what your NO3 and PO4 levels were at prior the addition of the rock and afterwards?

Retro Reefer · Sep 11, 2018

Dom said:
Ugh. I wonder why I was advised with "rinse and in..."?

"Cycling". Are you saying I should have cycled water in a bucket with the rock in it?

When I say cycle I’m referring to the process of establishing bacteria for biological filtration on your rock after it is cured/cleaned.. here is a video of how people will typically clean/cure dry rock.

saltyfilmfolks · Sep 11, 2018

Of the bat, It sounds to me like organics on the rock and bad advice.

If it was mined rock , it likey had no organics. And that would be odd.

If it was dry mined rock , it gets confusing for me here too as Randy F seems to disagree.
The soft minerals in the Aragonite dissolved as well as the outer layers of the calcium based “rock “ put into the salt water has been known to Create a large alk spike Esp in smaller water volumes. So if there were no “organics” (dead stuff) you still fed the tank a ton of other minerals and an inorganic carbon source.

Randy has long stated I belive , that aragonite is generally inert. That makes no sense to me as it’s just a less compacted limestone.

Dom · Sep 11, 2018

Let me be clear; I am not blaming anyone. It's my own fault, I should have consulted BEFORE putting the rock in.

Dom · Sep 11, 2018

My course of action: Weekly 25% water changes until the bacteria populates the new rock. It should self correct in time.

saltyfilmfolks · Sep 11, 2018

See it the Po4 is elevated and no3 as well. High no3 would be a mini cycle. Ammonia =no3 etc.

Check the alk as well and see if that’s odd.

Water changes will reduce the amount bacteria in the water and the amount will n the tank.

My .02.

Do you know if it was mined rock or other ?

Dom · Sep 11, 2018

saltyfilmfolks said:
See it the Po4 is elevated and no3 as well. High no3 would be a mini cycle. Ammonia =no3 etc.

Check the alk as well and see if that’s odd.

Water changes will reduce the amount bacteria in the water and the amount will n the tank.

My .02.

Do you know if it was mined rock or other ?

I purchased it in a rush. What's the expression; "nothing good ever happens fast in this hobby"?

Yes... hard to know what's going on without testing. I should have tested before posting.

My bad.

saltyfilmfolks · Sep 12, 2018

Dom said:
I purchased it in a rush. What's the expression; "nothing good ever happens fast in this hobby"?

Yes... hard to know what's going on without testing. I should have tested before posting.

My bad.

Happens to all of us.
Crud, I never test. Alk is pretty much it.

Water Dog · Sep 12, 2018

Do you have a link to the specific rock that you purchased? That will help us determine what may be happening. My guess would be that you bought some Reef Saver mined dryrock that has some bound phosphates on the surface layers of the rock.

Dom · Sep 12, 2018

https://www.bulkreefsupply.com/brs-reef-saver-dry-aquarium-live-rock.html

Water Dog · Sep 12, 2018

Okay, so that is mined dryrock. As I said in my post above, it is most likely leaching phosphates from the surface layers of the rock. Get yourself a Phosphate test kit and see what your PO4 levels are. Note however that you may get a false 0 reading if your algae bloom is consuming all of the PO4 from the water column. Put some GFO in a mesh bag and put it next to the Chemipure in your sump.

Now for treating the GHA. Because it seems like you just recently added the rock I’d suggest manual removal. Get rid of as much GHA from the rock as you physically can. Then, the next time you do a water change, reserve the waste saltwater in a small bucket. Remove the affected pieces pieces of rock and scrub it with a toothbrush dipped/soaked in white vinegar. Thoroughly scrub the algae infested surface area of each rock with the vinegar soaked brush. Rinse the cleaned rock in the buket of wasrewater and put back into your tank. Do this for all the infected rock. You will see bubbles forming on the rock surface and the algae will turn white and die. The next day do a 50% water change.

Continue to monitor PO4 levels in the tank and replace the GFO as needed. Once all the PO4 is leached from the rock, you could remove the GFO from your system. This removal of PO4 is part of the curing process that is often done before introducing new dryrock into a tank. The amount of bound phosphates in mined dryrock can vary from batch to batch. As an example, I have put ReefCleaners dryrock directly into an established tank before with no ill effects.

saltyhog · Sep 12, 2018

Be aware that your phosphate may not measure high due to the large algae load consuming it as it leaches from the rock. I had the same experience with mined rock. I had a mix of live rock and the mined rock and the hair algae was only on the mined rock. With good husbandry it will eventually go away.

Dom · Sep 13, 2018

As per my Red Sea test kit, my PO4 is at .08 right now. I'll test again in a day or so to determine if this is an upward trend.

I was planning on letting this run its course. I mean, eventually, leeching phosphates will run out. So could I get away with weekly 25% water changes until they do?

I am a minimalist and always prefer to let problems like this run their course. If this is a bad idea, I'd like to understand why.